flowable/flowable-engine · error · FlowableIllegalArgumentException

caseInstanceId is null

Error message

caseInstanceId is null

What it means

Thrown by SetVariableCmd.execute when caseInstanceId is null. Flowable's synchronous set-variable command validates its required arguments first and rejects a null case instance id with FlowableIllegalArgumentException before touching the database.

Source

Thrown at modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/cmd/SetVariableCmd.java:48

/**
 * @author Tijs Rademakers
 */
public class SetVariableCmd implements Command<Void> {
    
    protected String caseInstanceId;
    protected String variableName;
    protected Object variableValue;
    
    public SetVariableCmd(String caseInstanceId, String variableName, Object variableValue) {
        this.caseInstanceId = caseInstanceId;
        this.variableName = variableName;
        this.variableValue = variableValue;
    }
    
    @Override
    public Void execute(CommandContext commandContext) {
        if (caseInstanceId == null) {
            throw new FlowableIllegalArgumentException("caseInstanceId is null");
        }
        if (variableName == null) {
            throw new FlowableIllegalArgumentException("variable name is null");
        }
     
        CaseInstanceEntity caseInstanceEntity = CommandContextUtil.getCaseInstanceEntityManager(commandContext).findById(caseInstanceId);
        if (caseInstanceEntity == null) {
            throw new FlowableObjectNotFoundException("No case instance found for id " + caseInstanceId, CaseInstanceEntity.class);
        }
        caseInstanceEntity.setVariable(variableName, variableValue);
        
        CmmnEngineAgenda agenda = CommandContextUtil.getAgenda(commandContext);
        
        CmmnDeploymentManager deploymentManager = CommandContextUtil.getCmmnEngineConfiguration(commandContext).getDeploymentManager();
        CaseDefinition caseDefinition = deploymentManager.findDeployedCaseDefinitionById(caseInstanceEntity.getCaseDefinitionId());
        boolean evaluateVariableEventListener = false;
        if (caseDefinition != null) {
            CmmnModel cmmnModel = deploymentManager.resolveCaseDefinition(caseDefinition).getCmmnModel();

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Populate caseInstanceId before invoking setVariable
2. Add an explicit null/empty check at the call site
3. Fix the upstream code path that produced the null id

Example fix

// before
cmmnRuntimeService.setVariable(caseInstanceId, "k", "v");
// after
Assert.hasText(caseInstanceId, "caseInstanceId required");
cmmnRuntimeService.setVariable(caseInstanceId, "k", "v");

if (caseInstanceId == null || caseInstanceId.trim().isEmpty()) {
    throw new IllegalArgumentException("caseInstanceId must not be null or empty");
}

boolean hasCaseInstanceId(String id) { return id != null && !id.trim().isEmpty(); }

try {
    cmmnRuntimeService.setVariable(caseInstanceId, name, value);
} catch (FlowableIllegalArgumentException e) {
    log.error("Invalid argument for setVariable: {}", e.getMessage());
}

When it happens

Trigger: Calling setVariable on the CMMN runtime service with a null id, e.g. the id variable is uninitialized or derived from a lookup that returned null.

Common situations: Case start result not captured, null returned by an earlier engine call and propagated, missing request parameter in a service layer.

Related errors

• caseInstanceId is null
• variable name is null
• variable name is null
• caseInstanceId is null
• variables is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/6c3e18e2c08340de. Report an issue: GitHub.